Journal of the Atmospheric Sciences: Recent submissions
Now showing items 2761-2780 of 13215
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Convectively Coupled Equatorial Waves. Part III: Synthesis Structures and Their Forcing and Evolution
(American Meteorological Society, 2007)Building on Parts I and II of this study, the structures of eastward- and westward-moving convectively coupled equatorial waves are examined through synthesis of projections onto standard equatorial wave horizontal structures. ... -
Convectively Coupled Equatorial Waves. Part II: Propagation Characteristics
(American Meteorological Society, 2007)Following the description of the horizontal and vertical structures of convectively coupled equatorial waves presented in Part I, here their propagation characteristics are investigated. Linear lagged regressions are used ... -
Convectively Coupled Equatorial Waves. Part I: Horizontal and Vertical Structures
(American Meteorological Society, 2007)Multilevel 15-yr ECMWF Re-Analysis (ERA-15) and satellite-observed brightness temperature (Tb) data for the period May?October 1992 are used to examine the horizontal and vertical structures of convectively coupled equatorial ... -
Structure and Spacing of Jets in Barotropic Turbulence
(American Meteorological Society, 2007)Turbulent flows are often observed to be organized into large-spatial-scale jets such as the familiar zonal jets in the upper levels of the Jovian atmosphere. These relatively steady large-scale jets are not forced coherently ... -
Equatorial Jets in Decaying Shallow-Water Turbulence on a Rotating Sphere
(American Meteorological Society, 2007)Ensemble experiments of decaying shallow-water turbulence on a rotating sphere are performed to confirm the robustness of the emergence of an equatorial jet. While previous studies have reported that the equatorial jets ... -
Southern “Annular Modes” Simulated by a Climate Model—Patterns, Mechanisms, and Uses
(American Meteorological Society, 2007)Both high-latitude (HLM) and low-latitude modes (LLM) of variability of zonal wind in the Southern Hemisphere have been identified. Through an analysis of a simulation for 1871?2200 by the CSIRO Mark 3 climate model, the ... -
On the Arrest of Inverse Energy Cascade and the Rhines Scale
(American Meteorological Society, 2007)The notion of the cascade arrest in a ?-plane turbulence in the context of continuously forced flows is revised in this paper using both theoretical analysis and numerical simulations. It is demonstrated that the upscale ... -
Relations between Annular Modes and the Mean State: Southern Hemisphere Winter
(American Meteorological Society, 2007)In a zonally symmetric climatology with a single eddy-driven jet, such as prevails in the Southern Hemisphere summer, the midlatitude variability is dominated by fluctuations of the jet around its mean position, as described ... -
Asymmetrization Mechanism of Jet Profiles in Decaying β-Plane Turbulence
(American Meteorological Society, 2007)In a previous paper, asymmetry was found in jet profiles between eastward and westward jets, which appear spontaneously in two-dimensional ?-plane decaying turbulence. That is, westward jets are narrower and more intense ... -
Formation of Jets by Baroclinic Instability on Gas Planet Atmospheres
(American Meteorological Society, 2007)In this paper it is proposed that baroclinic instability of even a weak shear may play an important role in the generation and stability of the strong zonal jets observed in the atmospheres of the giant planets. The ... -
Numerical Simulations of Forced Shallow-Water Turbulence: Effects of Moist Convection on the Large-Scale Circulation of Jupiter and Saturn
(American Meteorological Society, 2007)To test the hypothesis that the zonal jets on Jupiter and Saturn result from energy injected by thunderstorms into the cloud layer, forced-dissipative numerical simulations of the shallow-water equations in spherical ... -
Eddy–Zonal Flow Interactions and the Persistence of the Zonal Index
(American Meteorological Society, 2007)An idealized atmospheric general circulation model is used to investigate the factors controlling the time scale of intraseasonal (10?100 day) variability of the extratropical atmosphere. Persistence on these time scales ... -
Jets and Orography: Idealized Experiments with Tip Jets and Lighthill Blocking
(American Meteorological Society, 2007)This paper describes qualitative features of the generation of jetlike concentrated circulations, wakes, and blocks by simple mountainlike orography, both from idealized laboratory experiments and shallow-water numerical ... -
Eddy–Zonal Flow Feedback in the Southern Hemisphere Winter and Summer
(American Meteorological Society, 2007)The eddy?zonal flow feedback in the Southern Hemisphere (SH) winter and summer is investigated in this study. The persistence time scale of the leading principal components (PCs) of the zonal-mean zonal flow shows substantial ... -
Two-Layer Baroclinic Eddy Heat Fluxes: Zonal Flows and Energy Balance
(American Meteorological Society, 2007)The eddy heat flux generated by statistically equilibrated baroclinic turbulence supported on a uniform, horizontal temperature gradient is examined using a two-layer ?-plane quasigeostrophic model. The dependence of the ... -
Dependence of Polar Low Development on Baroclinicity and Physical Processes: An Idealized High-Resolution Numerical Experiment
(American Meteorological Society, 2007)Polar low dynamics in an idealized atmosphere in which baroclinicity, stratification, and average temperature are varied in the typically observed range is investigated using a 5-km-resolution nonhydrostatic model. The ... -
The Very Stable Boundary Layer on Nights with Weak Low-Level Jets
(American Meteorological Society, 2007)The light-wind, clear-sky, very stable boundary layer (vSBL) is characterized by large values of bulk Richardson number. The light winds produce weak shear, turbulence, and mixing, and resulting strong temperature gradients ... -
Forced-Dissipative Shallow-Water Turbulence on the Sphere and the Atmospheric Circulation of the Giant Planets
(American Meteorological Society, 2007)Although possibly the simplest model for the atmospheres of the giant planets, the turbulent forced-dissipative shallow-water system in spherical geometry has not, to date, been investigated; the present study aims to fill ... -
A Coupled Atmosphere–Ocean Radiative Transfer System Using the Analytic Four-Stream Approximation
(American Meteorological Society, 2007)A coupled atmosphere?ocean radiative transfer model based on the analytic four-stream approximation has been developed. It is shown that this radiation model is computationally efficient and at the same time can achieve ... -
Empirical Master Equations. Part II: Application to Stratospheric QBO, Solar Cycle, and Northern Annular Mode
(American Meteorological Society, 2007)Time series of stratospheric climate variables are used to derive master equations in the discretized phase space spanned by three variables. The empirical master equation (EME) predicts the probability density function ...